Hot-air oven having an improved door-sealing member

ABSTRACT

A hot-air oven for the preparation of food is provided. A cooking chamber delimited by walls is provided in a housing. A blower produces a hot-air stream in the cooking chamber, and a controller controls the progress of a cooking process. A rotatable basket for food can be introduced into the cooking chamber via an opening in one of the walls. During operation the basket is subjected to a hot-air stream. A closure element is connected to the basket and serves to close off the wall opening during operation. The closure element is supported relative to the basket via a pivot bearing that is coaxial with an axis of rotation of the basket.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a hot-air oven for thepreparation of food. The oven includes a housing that has a cookingchamber delimited by four side walls, one of which can be embodied as adoor, as well as a bottom wall and a top wall. A blower means isprovided for producing a hot-air stream in the cooking chamber. Acontrol means is also provided for controlling the progress of a cookingprocess. A rotatable basket is provided for food and can be introducedinto the cooking chamber via an opening in one of the walls, wherebyduring operation a hot-air stream passes through the basket. Inaddition, during operation the wall opening is closed off by a closureelement that is connected to the basket.

[0002] A hot-air oven of this type is known, for example, from theEuropean Patent EP 0734503 B1. In such a hot-air oven, a basket for theproducts that are to be prepared is mounted in a cooking chamber so asto be rotatable about an axis. The basket can be withdrawn out of thecooking chamber in the axial direction, and is provided on its free endwith a round closure plate that is disposed concentric to the axis ofrotation. This closure plate is fixedly connected with the basket, andwhen the basket is completely inserted seals off the cooking chambertoward the outside. A seal is provided between the housing, which isstationary during operation, and a similarly stationary, pivotable dooron the one hand and the rotating closure plate on the other hand; duringoperation, the seal is similarly stationary and the closure plate of thebasket slides over the sealing surfaces of the seal. This form of thesliding seal in practice, especially after longer periods of operation,leads to sealing problems. In this sealing region, steam from thecooking chamber, or smoke that might develop, can escape, which inaddition to the possible formation of odor can also make the surface ofthe oven dirty.

[0003] It is therefore an object of the present invention to improve ahot-air oven of the aforementioned general type in such a way that thesealing of the cooking chamber is improved in the region of the removalopening for the basket.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] This object, and other objects and advantages of the presentinvention, will appear more clearly from the following specification inconjunction with the accompanying schematic drawings, in which:

[0005]FIG. 1 is a perspective view of one exemplary embodiment of aninventive hot-air oven; and

[0006]FIG. 2 is a cross-sectional view through the sealing region of thedoor of the hot-air oven of FIG. 1.

SUMMARY OF THE INVENTION

[0007] The hot-air oven of the present invention is characterizedprimarily in that the closure element is supported relative to thebasket in a pivot bearing that is coaxial with the axis of rotation ofthe basket.

[0008] Since the closure element is supported relative to the basket ina pivot bearing that coincides with the axis of rotation, the basket canbe rotated during operation while the closure element remainsstationary. The closure element is preferably provided with a sealingzone that is circular cylindrical and rotationally symmetrical relativeto the support axis. In this connection, the seal, which is associatedwith the housing of the door, is preferably disposed against the outerperipheral surface of the cylindrical region of the closure element. Tosimplify handling, it is furthermore possible to provide a handle onthat surface of the closure element that faces away from the cookingchamber. By means of this handle, the basket can be withdrawn out of thecooking chamber. The operation can be made particularly reliable if, asa function of a control means, the basket is withdrawn out of thecooking chamber only when an opening provided on the basket is directedupwardly. To empty the basket, it is furthermore advantageous for thebasket to be rotatable, by means of a motor, out of this position andinto a discharge or issuing position. Pursuant to a particularlystraightforward embodiment of the inventive hot-air oven, when thebasket is withdrawn from the cooking chamber a mechanically fixedcoupling is effected between the closure element and the basket. Thiscan be effected by a manual actuation of a coupling or catch that isassociated with the handle.

[0009] Further specific features of the present invention will bedescribed in detail subsequently.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0010] Referring now to the drawings in detail, a hot-air oven isillustrated in perspective in FIG. 1. The hot-air oven has three fixedside walls 2 as well as a side wall 4 that is provided with a door 3 andthat is to be opened. The upper side is formed by a top wall 5, and theunder side is formed by a non-visible bottom wall. The walls 2-5surround the interior of the hot-air oven, a portion of which isembodied as a cooking chamber.

[0011] The side wall 4 and the door 3 have a circular opening 7 throughwhich a mesh-type basket 8 can be introduced into the cooking chamber.

[0012] The basket 8 is rotatably mounted in the cooking chamber in amanner known per se. During operation, a hot-air stream passes throughthe basket, which is rotated about an axis that is parallel to thedirection of insertion and that coincides with the axis of symmetry ofthe opening 7.

[0013] At one end face, the basket 8 is provided with a closure element10 that has a handle 11 for pulling the basket 8 out or pushing it in.

[0014] The region of the opening 7, and the outer end of the basket 8,are illustrated in greater detail in the cross-sectional view of FIG. 2.The same components have the same reference numerals.

[0015] In addition to the circular disc shaped outer portion of theclosure element 10 that is visible in FIG. 1, and to which the handle 7is fastened, the closure element has a cup-shaped portion 13 that isembodied to be rotationally symmetrical about an axis of rotation 14,and that is welded or otherwise fused to the outer portion of theclosure element 10. Disposed centrally and perpendicular to the closureelement 10 is a bearing or support pin 15 that passes through theportion 13 and in the direction toward the basket 8 extends beyond thebasket. The pin 15 carries two bearing discs 16, which are disposed oneither side of an end face 17 of the basket 8. A central sleeve spacesthe discs 16 apart, so that the end face 17 of the basket 8 remainsrotatable about the axis 14 between the discs 16. A cap nut secures thediscs 16 to the pin 15.

[0016] The door 3, which is provided with the opening 7 that issimilarly disposed approximately concentrically relative to the axis 14,is, for receiving the described closure element 10, provided with asealing means 20 that is made of an elastomeric or rubber-elasticmaterial and is provided with a free sealing lip 21 that faces theclosure element 10.

[0017] During operation, the interior of the basket 8 can be filled withfood, for example frozen french fries. The basket 8 is then inserted viathe handle 11, in the direction of the axis 14, into the housing of thehot-air oven 1, stated more precisely into the cooking chamber, as aresult of which the sealing lip 11 of the sealing means 20 rests againstthe outer peripheral surface 13 of the cup-shaped portion of the closureelement 10. The cooking chamber is thereby sealed off relative to theouter atmosphere. That portion of the closure element 10 that projectsradially beyond the peripheral surface 13 secures the region of thesealing means 10 and the sealing lip 20 against external contact andalso optically seals the cooking chamber.

[0018] To cook the food, the basket 8 is rotated about the axis 14 andis subjected to a hot-air stream. In this connection, the end face 17 ofthe basket 8 also rotates about the axis 14 between the discs 16, whilethe closure element 10, with its attached parts, remains stationary. Thesealing of the cooking chamber in the region of the contact surfacebetween the sealing lip 21 and the outer peripheral surface 13 isstationary due to the mechanical uncoupling in the region of the pivotbearing formed by the elements 16 and 17.

[0019] When the cooking process is concluded, the basket 8 is rotatedinto a starting position in which its basket opening is toward the top.Via the handle 11, the basket 8 can then be pulled out of the housinguntil it abuts thereagainst. The opening of the basket is then rotateddownwardly by a motor, so that the food product issues from the basket8.

[0020] Pursuant to another embodiment, the rotation of the basket into adischarge position by motor can be replaced by a manual rotation via thehandle 11. For this purpose, a fixed coupling, which is not illustratedin FIG. 2, is required that engages only when the basket 8 is withdrawnout of the cooking chamber.

[0021] On the whole, there results a sealing of the hot-air oven in theregion of the door 3 that, relative to the state of the art, and as aconsequence of the sealing elements, of the sealing means 20 with itssealing lip 21, and of the peripheral surface 13, which are stationaryrelative to one another during operation, ensures a considerablyimproved and more durable sealing of the cooking chamber relative to theatmosphere.

[0022] The specification incorporates by reference the disclosure ofGerman priority document 10 207 638.3 of Feb. 22, 2002.

[0023] The present invention is, of course, in no way restricted to thespecific disclosure of the specification and drawings, but alsoencompasses any modifications within the scope of the appended claims.

1. a hot-air oven for preparation of food, comprising: a housing having a cooking chamber that is delimited by four side walls one of which can be embodied as a door, as well as by a bottom wall and a top wall; a blower means for producing a hot-air stream in said cooking chamber; a control means for controlling progress of a cooking process; a basket for food, wherein said basket is rotatable and is introducible into said cooking chamber via an opening in one of said walls, wherein during operation said basket is subjected to a hot-air stream; a closure element that is connected to said basket and serves to close off said wall opening during operation; and a pivot bearing that is coaxial with an axis of rotation of said basket, wherein said closure element is supported relative to said basket via said pivot bearing.
 2. A hot-air oven according to claim 1, wherein said closure element is provided with a sealing region that is circular cylindrical or annular and is rotationally symmetrical relative to said axis of said rotation.
 3. A hot-air oven according to claim 2, wherein a sealing means is provided that during operation is stationary and that is associated with said housing or said door, and wherein said sealing means rests against an outer peripheral surface of said sealing region.
 4. A hot-air oven according to claim 1, wherein a surface of said closure element that faces away from said cooking chamber is provided with a handle for withdrawing said basket out of said cooking chamber.
 5. A hot-air oven according to claim 1, wherein as a function of said control means, said basket can be withdrawn from said cooking chamber only if in a normal position an opening provided on said basket is directed upwardly.
 6. A hot-air oven according to claim 5, wherein said basket is rotatable out of said normal position into a discharge position.
 7. A hot-air oven according to claim 6, wherein said basket is rotatable by means of a motor.
 8. A hot-air oven according to claim 1, wherein a mechanically fixed coupling is provided between said closure element and said basket, and wherein said coupling is in engagement when said basket is withdrawn from said cooking chamber.
 9. A hot-air oven according to claim 8, wherein said coupling is effected by a manual actuation of a coupling or catch that is associated with a handle of said closure element. 